Typhus

Question 1

Organisms causing typhus?

Answer 1

Vector borne diseases caused by rickettsiae
Scrub typhus- orientia tsutsugamashi (vector - trombiculid mite)
Endemic typhus - rickettsia typhi (vector- rat flea)
Epidemic typhus - rickettsia prowazeki (vector-human body louse)

Question 2

Pathophysiology of typhus?

Answer 2

Local - inflammatory response

General- vasculitis many organs involved, endovasculitis also causes rashes and bleeding diathesis

Question 3

Clinical features of typhus?

Answer 3

Incubation period- 2 w
Acute- begin abruptly as swinging fever, frontal headache, myalgia, conjunctival injection
End of 1st w- generalized lymphadenopathy, meningism, hepatospleenomegaly,rash

Eachar- virtually diagnostic

Question 4

Complications of typhus?

Answer 4

Pulmonary 
- pneumonia 
- pleural effusion 
Neurological 
- various degrees of meningitis 
- encephalopathy 
- deafness and tinittus
Rare liver and renal failure

Question 5

Ix and Mx of typhus?

Answer 5

Ix-
Weil felix reaction
Main confirmatory- indirect immune peroxidase test and indirect immune fluorescent test
FBC- leucopenia, slight neutrophilia, thrombocytopenia

Mx-
Tetracycline (dramatic response) doxycycline given as therapeutic trial
Chloramphenicol,fluroquionolone also respond
10 day duration